• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.66-66
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• 2000

In this parer, we introduce an algorithm to control flows of the traffic in multi-intersections. It is pointed out that the main problem in traffic control is how to resolve the congested situations for the particular time-durations and directions. The heavy load to a certain direction usually leads the intersection to congested situations, and the adjacent intersections are affected. We control and analyze the traffic flow of multi-intersections consisting of five intersections, in which four intersections are linked to the four directions of the central one. The entrance of vehicles of each direction is described using the concept of probability. We compare the performance of the pretimed signal controls to the traffic adaptive signal controller using a Petri Net simulation tool, Exspect.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권5호
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• pp.591-595
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• 2010

본 논문에서는 자동화 컨테이너 터미널에서 컨테이너를 운반하는데 사용되는 무인 운반 차량(AGV)의 교통흐름을 동적으로 최적화하는 방안을 제안한다. 터미널 환경은 다수의 차량이 한정된 영역 내에서 주행하므로 높은 생산성을 위해서는 차량 사이의 간섭 및 병목현상을 최소화하도록 교통흐름을 제어해야 한다. 제안 알고리즘은 터미널 환경의 동적 변화에 대응하여 유전알고리즘을 이용하여 AGV의 교통흐름을 최적화한다. 알고리즘의 속도향상을 위해 이전에 수행한 최적화 결과를 활용하는 방안이 시도되었다. 시뮬레이션 실험을 통해 제안 알고리즘의 성능을 확인하였다.

• 대한교통학회지
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• 제23권3호
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• pp.137-147
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• 2005

본 연구의 목적은 연속류의 미시적 행태분석을 통해 새로운 용량개념을 정의하고 이에 대한 용량 산정방법을 개발하고 제안하는데 있다. 교통자료 검지체계의 기술적 발전은 기존 미국 도로용량편람에서 활용된 자료에 비해 정확하고 많은 자료의 수집을 가능하게 하고, 이에 따라 교통류 해석에 대한 다양한 학문적 접근이 시도되면서 기존도로용량의 정의와 산정기준의 한계점이 드러나고 있다. 대안적 용량개념은 교통류-밀도 관계에서 용량감소와 이력현상을 포함한 혼잡교통류의 특징을 포괄적으로 해석하려는 시도로써, 확률적 모형과 행태적 또는 역학적 모형으로 구분할 수 있다. 그러나 대안적 용량개념으로 제안된 두 가지 모형 역시 연속류의 다양한 상태와 상태변동을 설명하기에는 한계점을 가지고 있다. 본 연구에서는 이러한 한계를 극복하기 위하여, 연속류의 미시적 행태자료를 통해 시추이 속도-밀도 관계. 집계간격과 교통량-속도-밀도 관계, 차두시간 분포특성, 그리고 자유속도 분포특성 분석을 수행하고, 용량의 기준이 되는 차두시간을 통계적으로 결정함으로써 교통제어를 위한 새로운 용량개념을 정의하고 이에 대한 용량산정방법을 개발하였다.

• 인터넷정보학회논문지
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• 제22권6호
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• pp.1-8
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• 2021

With the rapid growth of intelligent devices and communication technologies, 5G network environment has become more heterogeneous and complex in terms of service management and orchestration. 5G architecture requires supportive technologies to handle the existing challenges for improving the Quality of Service (QoS) and the Quality of Experience (QoE) performances. Among many challenges, traffic steering is one of the key elements which requires critically developing an optimal solution for smart guidance, control, and reliable system. Mobile edge computing (MEC), software-defined networking (SDN), network functions virtualization (NFV), and deep learning (DL) play essential roles to complementary develop a flexible computation and extensible flow rules management in this potential aspect. In this proposed system, an accurate flow recommendation, a centralized control, and a reliable distributed connectivity based on the inspection of packet condition are provided. With the system deployment, the packet is classified separately and recommended to request from the optimal destination with matched preferences and conditions. To evaluate the proposed scheme outperformance, a network simulator software was used to conduct and capture the end-to-end QoS performance metrics. SDN flow rules installation was experimented to illustrate the post control function corresponding to DL-based output. The intelligent steering for network communication traffic is cooperatively configured in SDN controller and NFV-orchestrator to lead a variety of beneficial factors for improving massive real-time Internet of Things (IoT) performance.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1328-1332
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• 2010

The enlargement of existing tunnels is required to cope with problems related to traffic congestion. Sometimes, the tunnel traffic must be maintained through existing tunnels during their reconstruction due to non-availability of detours. And excavation by drill and blasting is desired for widening a hard rock tunnel. In this case, the road must be closed for some period for blasting through analyzing of traffic volume. In this paper, a case study on some traffic countermeasures for tunnel enlargement by blasting was performed. And the traffic flow characteristics of some tunnels in domestic main city were analyzed.

• Structural Engineering and Mechanics
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• 제70권2호
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• pp.169-178
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• 2019

The replacement of damaged components is an important task for long-span bridges. Conventional strategy for component replacement is to close the bridge to traffic, so that the influence of the surrounding environment is reduced to a minimum extent. However, complete traffic interruption would bring substantial economic losses and negative social influence nowadays. This paper investigates traffic control technologies without interruption for component replacement of long-span bridges. A numerical procedure of traffic control technologies is proposed incorporating traffic microsimulation and site-specific data, which is then implemented through a case study of cable replacement of a long-span cable-stayed bridge. Results indicate traffic load effects on the bridge are lower than the design values under current low daily traffic volume, and therefore cable replacement could be conducted without traffic control. However, considering a possible medium or high level of daily traffic volume, traffic load effects of girder bending moment and cable force nearest to the replaced cable become larger than the design level. This indicates a potential risk of failure, and traffic control should be implemented. Parametric studies show that speed control does not decrease but increase the load effects, and flow control using lane closure is not effectual. However, weight control and gap control are very effective to mitigate traffic load effects, and it is recommended to employ a weight control with gross vehicle weight no more than 65 t or/and a gap control with minimum vehicle gap no less than 40 m for the cable replacement of the case bridge.

• 제어로봇시스템학회논문지
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• 제5권8호
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• pp.907-913
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• 1999

For an automated transportation system like PRT(Personal Rapid Transit) system or IVHS, an efficient vehicle-merging algorithm is required for smooth operation of the network. For management of merging, collision avoidance between vehicles, ride comfort, and the effect on traffic should be considered. This paper proposes an unmanned vehicle-merging algorithm that consists of two procedures. First, a longitudinal control algorithm is designed to keep a safe headway between vehicles in a single lane. Secondly, 'vacant slot and ghost vehicle' concept is introduced and a decision algorithm is designed to determine the sequence of vehicles entering a converging section considering energy consumption, ride comfort, and total traffic flow. The sequencing algorithm is based on fuzzy rules and the membership functions are determined first by an intuitive method and then trained by a learning method using a neural network. The vehicle-merging algorithm is shown to be effective through simulations based on a PRT model.

• Journal of Communications and Networks
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• 제5권3호
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• pp.230-239
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• 2003

In this paper, we propose a framework to study how to route packets efficiently in multipath communication networks. Two traffic congestion control techniques, namely, flow assignment and packet scheduling, have been investigated. The flow assignment mechanism defines an optimal splitting of data traffic on multiple disjoint paths. The resequencing delay and the usage of the resequencing buffer can be reduced significantly by properly scheduling the sending order of all packets, say, according to their expected arrival times at the destination. To illustrate our model, and without loss of generality, Gaussian distributed end-to-end path delays are used. Our analytical results show that the techniques are very effective in reducing the average end-to-end path delay, the average packet resequencing delay, and the average resequencing buffer occupancy for various path configurations. These promising results can form a basis for designing future adaptive multipath protocols.

• 대한교통학회지
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• 제27권1호
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• pp.27-34
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• 2009

도로교통망의 시스템변화에 대한 효과분석의 일환으로 1979년 Herman이 제시한 Two-Fluid Model을 적용하여 거시적인 교통류 변화특성을 분석하였으며, 이를 통해 도로시설의 운영개선 효과를 정량적으로 확인하였다. 본 연구에서는 일반국도 3호선 의정부 전체 구간의 약 8km, 총 31개 신호교차로를 분석 대상으로 하며, TSIS CORSIM 및 Run Time Extension을 이용한 미시적 시뮬레이션 분석으로 현황 및 개선 대안에 대한 개별차량의 주행정보를 추출하였다. Two-Fluid Model의 파라메타 산출결과 현황 대비 신호제어시스템 개선 시 네트워크의 서비스 질을 의미하는 단위거리 당 평균최소통행시간(Tm)은 약 35% 감소하였으며, 네트워크 수요증가에 대한 저항성을 의미하는 파라메타 n은 약 28%의 향상된 결과를 나타내었다. 국도 축을 대상으로 하는 시뮬레이션 기반의 자료 수집으로 인해 제한된 연구결과이나 Two-Fluid Model이 신호 최적화 및 연동형 반감응제어의 적용 등 신호제어시스템 개선에 대한 우수한 거시적 효과평가 지표로 활용되어 질 수 있음을 확인하였다.

• 한국항해학회지
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• 제15권3호
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• pp.1-11
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• 1991

As increasing needs of marine transportation , world merchant fleet and ship's size were enlarged and it caused frequent disasters in human lives and natural environment. By the reason of the above, they started to establish the Vessel Traffic System (VTS) at the European coast in 1960' and most of advanced contries established and managed it to prevent the sea traffic accidents in these days. The concept of traffic control at sea can be divided into three types. First, the initial gathering of informations about ship's identity and movement etc.. Second, monitoring of the traffic flow and amendment of instructions. Third , organization and direction of ships by allocating routes and speeds. Where the goal of traffic control is safety of traffics and developing effectiveness of navigation channel, if traffic volume is less tan channel capacity then the above first or second level of control would be sufficient but if it is bigger than that , more positive policy of control should be adopted as same as third type of the above. In this paper where the strategy of VTS is focused on the control of traffic density to be spread equality, as possible , all over the navigation channels and also improvement of effectiveness , it suggests algorithm to assign the vessels to the channels with balanced traffic density , and other algorithms using D.P. to sequence the vessels assigned to one channel in optimum order which decreases the mean waiting time in sense of channel effectiveness with numerical examples.